How do the vibrations of the pipeline flow measurement with a Vortex flow meter?
One would expect that a vortex flowmeter for measuring principle is based, react negatively to strong vibration and shock pressure.
However, the DSC sensors E + H devices have primary vibration damping to compensate even higher than lg (9.81 m / s 2, 32 ft / s 2) in all axes.
Figure: Measuring a flow of liquid nitrogen (-190 ° C, 25 bar / -310 ° F, 360 psi).
How do they affect the measurement of liquid flow the intrusive presence of solid particles or gases in the fluid?
In general, there should be a single liquid phase, in other words, it should contain mixture of gases or solids.
- The intrusion of gas into the liquid causes a measurement error of plus sign. In these circumstances, or Vortex flowmeter is mounted with the solid body and shovel in a horizontal position sensor or the sensor at the bottom of the pipe. This method can not be measured gaseous.
- If the amount of particulate solid intrusive, for example, rust or paint. pipe, it is important to install the sensor will be in a position which is not covered by the particles. In these cases, we recommend mounting the sensor and electronics horizontally or on the top of the pipe.
- The accumulation of solid particles or in the measuring tube changes the geometry of these components, and therefore, the parameter K, which ultimately leads to measurement errors.
What is the effect of wet steam flow measurement?
Only measures the flow of steam, but does not include the Gothic water that may have mixed.
Fig ozone flow measurement applications in water treatment.
What effect does the presence of abrasives in the fluid flow measurement?
A strong abrasive reaction will inevitably change the velocity profile in the solid body because the dumb vortex shedding edges are blurred. The parameter K will shift and will produce a negligible measurement error.
How do they affect the measurement of Reynolds numbers less than 20,000?
Flow measurements with Reynolds numbers less than 20,000 are affected by an additional error because the vortex shedding behind the solid body fails to be completely regular (see nomogram Page 424). This error can be compensated in the range of Reynolds numbers ranging from 4,000 to 20,000 if the process parameters (type of fluid, pressure, temperature and viscosity) are known. The vortex shedding for Reynolds numbers below 4,000 is more arbitrary, the frequency of detachment is more indeterminate, and the measurement practice is negligible, or simply impossible.
What are the consequences using the device for measuring fluid flow at rates higher than the maximum specified?
For many fluids, measurements of the fluid at speeds above 9 m / s (30 ft / s) cause errors due to cavitation. The pressure drop also is likely to be relatively high. The selection and design software. "Applicator" E + H, incorporates functions to determine when cavitation is expected for a certain process conditions. Gas Flow speeds above 75 m / s (245 ft / s), load losses can be high enough to counter such a not economically profitable.
What if I do not take into account the input and output sections recommended?
For the execution of Vortex flow meters are correct, it is necessary that the formation of vortices at the sides of the solid body is at a regular pace. This requires a well-defined velocity profile at the counter. Disturbances in the ñujo due to the presence of upstream fittings (valves, elbows, etc.) Can cause significant measurement errors. To avoid this, are necessary input sections upstream of a minimum length of 10 to 40 times the nominal diameter, depending on the type of obstruction. Each manufacturer specifies the required input section for a particular device. The inbound leg length can be reduced up to 10 times the nominal diameter, installing a flow conditioner (perforated disc).
The outlet pipe section (rnínimo 5 times the nominal diameter) behind the Vortex flowmeter must be sufficiently long to allow the free formation of vortices downstream of the solid body.
How does it affect a pulsating flow measurement?
After a certain pulse frequency, Vortex flowmeters are unable to distinguish the measurement signal superimposed pulse signal, and you get an incorrect reading of the flow velocity.
What if the pipe is not completely full?
In general, Vortex flowmeters are unable to take action in these conditions.
How do the density and viscosity of the fluid flow measurement?
Within the field of values "linear" permissible Reynolds numbers (where the Strouhal number remains constant), the density and viscosity have no effect on the accuracy of measurement, although it may reduce the value fields measure. This remains true if the Reynolds number is less than 20,000, in which case, the accuracy of the measurement is inevitably reduced. Therefore, the density and viscosity influence the measurable minimum flow.
How does the fluid temperature measurements?
The counter body expands with temperature, more or less depending on the material they are made, and thus also changes the parameter K. The value of this parameter for the stainless steel is around 0.5% per 100 K. You can compensate for these effects by introducing the fluid temperature transmitter.
Why Kno parameter depends on the type of fluid (liquid, gas)?
The parameter K is completely independent of the fluid because it only depends on the geometry of the counter.
What factors should be taken into account when installing a vortex flowmeter in a pipe?
The walls of the inlet and outlet sections of the pipe should not have welds, burrs or protruding boards. This is very important to ensure no disruption of flow velocity profile. Furthermore, the position of the counter should be well in the center of the pipe. In addition, the nominal diameter and the inside diameter of the pipe should be as close as possible. If the difference between these two diameters is greater than allowable, you can program in electronics a compensating factor.
What are the effects of deposits of foreign matter in the DSC sensor?
Unlike other types of sensors, the DSC sensor is completely insensitive to the presence of foreign matter because it floats freely downstream of the solid body. They have conducted experiments with the sensor hole completely filled with resin, and even then, there has been no discernible effects on the measurement.
